1. Field of the Invention
The present invention relates to a method and a device for forming a molded portion at an end of an extruded weather strip.
2. Description of the Prior Art
A weather strip for attachment around a body opening or a door of a motor vehicle is generally made of an elastic material, particularly rubber or synthetic resin, and is generally formed by extrusion.
In order to shape an end of the extruded weather strip to a desired configuration, an end portion has been connected thereto by molding. And also, ends of two extruded weather strips have been connected by molding (see, for example, U.S. Pat. No. 4,884,370).
The above-described molding has been performed by closing a mold composed of a plurality of mold members with an end of an extruded weather strip placed in a cavity defined by the mold members, and injecting a molding material into the cavity.
Upon closing of the mold, the end of the extruded weather strip is forcibly compressed by the mold members in order to prevent the molding material from leaking out of the cavity, and in order to prevent the end surface of the extruded weather strip from being deformed due to the injection pressure of the molding material. Accordingly, when the mold is opened after molding, the end of the extruded weather strip expands and returns to its original uncompressed shape. This causes the generation of a step between adjacent surfaces of the extruded weather strip and the molded portion.
FIGS. 7 and 8 illustrate the state where the above-described step is generated upon closing of a mold M.
In the drawings, an end of an extruded weather strip is placed between a fixed mold member 2 and a movable mold member 3, and clamped by a clamping amount C.
A molding material is injected into a cavity 4 defined by the fixed mold member 2 and the movable mold member 3 to form a molded portion 1B. When the mold M is opened after molding, the end of the extruded weather strip 1A expands by the amount substantially equal to the clamping amount C. As a result, a step S is generated between the extruded weather strip 1A and the molded portion 1B. This step S is particularly large in the case where the extruded weather strip 1A is made of a foamed material.
Recently, the appearance of various parts of a motor vehicle has been improved. And the appearance of the molded portion of the weather strip has been also required to be improved.
However, the above-described step causes the deterioration of the appearance of the molded portion. Also, this step causes the decrease in sealing performance of the resulting weather strip.